How do I color the shading of a material?
This is something you can do very easily in the Blender Internal renderer, where, unlike Cycles, you can feed the output of light's interaction with a surface back into the calculation. 

In Cycles, this would lead to a feedback loop: (lighting affects surface affects lighting affects....), so there, you would have break the loop by baking the outcome of one light/surface interaction as, say, a diffuse texture,  and use it to influence a  second.

Simplest sort of node setup:



(You can use the shading output any way you like)

Result..



In Cycles, you could find a more physically-based route to a specific effect you were looking for .. perhaps subsurface scattering, translucency, fresnel...